北西地震带地震活动空间的模糊时间分维  

FUZZY TEMPORAL FRACTAL DIMENSION OF SEISMIC ACTIVITY REGIONS ON NORTH-WESTERN SEISMIC ZONE

作　　者：刘砚越[1] 

机构地区：[1]天津市地震局

出　　处：《华北地震科学》1994年第1期28-34,共7页North China Earthquake Sciences

摘　　要：选用北西地震带１９７０年至１９９０年２１年地震资料，对所发生地震的模糊时间分维结构进行了分析和研究。分别以二个月为一个单位和一年为一个单位计算了模糊时间维数Ｄｏ并绘出以二个月Ｄｏ随ｔ变化和２１年每年Ｄｏ随ｔ变化曲线。为了更好突出中强震选取了覆盖北西地震带６个面积相等小区，分别进行了模糊时间分维计算，求出每年６个Ｄｏ来，再（１／６）ΣＤｏ，计算出每年的平均Ｄｏ来并绘出每一小区二个月Ｄｏ随ｔ变化和２１年每年Ｄｏ随ｔ变化曲线。经计算可得以下结果。（１）多数较强地震之前Ｄｏ明显降低。（２）六小区模糊时间分维Ｄｏ随ｔ变化特征可识别地震带不同区域活动性。（３）可划分未来发生较强震所在地区。By selecting 21 years' seismic data along the North-western zone from 1970 to 1990, the fuzzy temporal fractal dimensions (Do) of the earthquakes occurred during the period are analysed and studied. The fuzzy temporal fractal dimensions are calculated in this paper on 2-month and 1-year basis respectively and the curves are plotted to show the Do～variation with time t in every 2-month as well as every year during the studied 21 years. To be more outstanding for moderately-strong earthquakes,the fuzzy temporal fractal dimensions of the earthquakes are calculated respectively by selecting 6 small equal areas civering the north-western seismic zone so as to obtain 6 Do in every year, then 1/6 ΣDo and the curves are plotted to show the Do～variation with time t in every 2 months as well as every year during the studied 21 years for each small area. The calculated results are as follows:1. The Do decreases before most of strong earthquakes.2. Based on the variations of fuzzy temporal fractal dimentions with time t in the 6 small areas, the activity of each area of the seismic zone may be recognized.3. The regions of the coming strong earthquakes can be determined

关 键 词：模糊时间分维 地震带 地震活动性 

分 类 号：P315.5[天文地球—地震学]